I decided to make it for my future electric projects. It's cheaper and more interesting than buy completed one.
Please, watch the video. There I'm showing tests and checking each of the components. You'll see electrical sparks by short circuit 220V and 24V, also test of maximum load.
Video:Parts:Step1:Power Socket (№2 in the pic.1)
It has a 10 amperes fuse.
It means if we connect any electrical appliance, which consumes more than 10 amperes, the fuse will be blown and protect our circuit (blowing and short circuit protection test in the video).
Step2: AC to DC power Converter (№3 in the pic.1)
The main part of our project is AC to DC power Converter.
- Input: AC, 85... 265V.
- Output: DC, U=24V.
- Maximum load I ≈ 4 Amp. It gives us P = 24 * 4 ≈ 100W
The Power Converter has an overload protection and short circuit protection (test in the video).
Step 3: Voltage and Current Regulator (№4 in the pic.1)
- Input: DC, 7... 32V.
- Output: DC, 1.3... 28V.
- Maximum Output current I ≈ 8 Amp.
Let's replace small potentiometers with large Precision Potentiometers.
Step 4: Precision Potentiometers (№5 in the pic.1)
I used these Precision Potentiometers (R=10 kOhm). It is more accurate then single-turn potentiometers.
Pin layout:
- old Potentiometers: 1-2-3
- new Potentiometers: 2-1-3.
Be careful and solder, as in the picture.
Step 5: Voltage and Amperage Monitor (№7 in the pic.1)
There are several models of voltage and current monitors. I advise you to buy with 4 numbers, because monitors with 3 numbers have less accuracy. Also use a 10A monitor for this project, because the 50A monitors do not work with low current.
- Working voltage: DC4V-28V
- Measuring Range: DC 0-200V, 0-10A.
(watch check in the video)
Step 6: Cooler (№9, 10, 11 in the pic.1)
Now, if we want to use our bench power supply in a case, or for a long time, or use it at full capacity, we need to add a cooler.
The type of cooler depends on the case. But now I'm going to use only this 40mm fan (№11 in the pic.1). This is a 12V fan. So, we need to use a mini DC power converter to get 12V from 24V (№9 in the pic.1). There is a voltage regulator.
The last part for today is a Temperature Controller (№10 in the pic.1). It has a temperature sensor, indicator and relay.
You can configure at what temperature the fan will turn on and at what temperature it will turn off. Depends on you case.
Just connect all modules like in the picture.
The hottest point of my circuit is AC-DC Converter's radiator. I put the temperature sensor into it. I'm gonna glue it using Thermal Compound Paste in the future.
I used:
- 1.0 mm² - for all main power parts (I=10A max);
- 0.25 mm² - for potentiometers, fan, temperature controller.
So, today we've made our own 120W Bench Power Supply.
This is "easy to repeat" project. So, if you want to do something like this, please, ask your questions in the comments, I'll help you.
And watch the video, there are several tests.
Thank you, bye!
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